Level 3: Gumshoe

Telstra C6300 port forwarding not working



My name is Jamie Wright and I am a software developer as well as a hardware technician.


I recently purchased the Telstra Gateway Max (Netgear C6300) and would like to advise that the port forward, DMZ and UPNP features do not work even though they are present in the modem routers settings.


After hours of trial and error and research I have found that this particular router has bugs and requires a firmware fix in order to allow ports to open. I run a full time business and have a server as well as cameras I need to access externally and need to open ports to be able to get into my internal network.


If you don’t believe that there is a serious issue with this router, here are some links from a simple search result "netgear c6300 port forwarding not working" or "telstra gateway max port forwarding" and you will see there are a lot of other people having this issue. Here are some links:










I would like to know when this issue will be fixed as this is critical to my business and needs to be resolved because netgear and Telstra are selling modem routers that are broken. 


FYI, I have an old G3100 Telstra modem here that I tried and port forwarding works a treat however I have purposely upgraded to this C6300 for better wireless capabilities and now I’m running into this serious issue. I also tried to set the C6300 in DMZ mode and it doesn’t allow any ports to function through this mode therefore all access to my internal network are blocked.


Please advise if there a fix in place or when there will be a fix so this can be sorted. If it can’t be sorted then I will need to seek advice from the ACCC or I will need to cancel my cable connection.



Jamie Wright.


Was this helpful?

  • Yes it was, thank you
  • No, I still need help
Level 25: The Singularity
Level 25: The Singularity

Re: Telstra C6300 port forwarding not working



I can sympathise with your situation.


Unfortunately, unless your internet connection is set up as a business account, then I don't htink there is any comeback. As the C6300 isn't advertised by Telstra as having Port Forwarding, DMZ or UPNP features, then I don't believe that the ACCC will be able to help.


If you are on a business account and Telstra have agreed to supply equipment to enable these features, then you would have a case.


I agree that these features should be working on any modern Modem/Router and it is very disappointing (and hence why I don't use a Telstra supplied modem - no cable either) that it doesn't work on this model.  Your best bet would be to contact Netgear and see if they have a solution (they develop the firmware).


The other option is to by a second Router and put the Telstra Cable modem into bypass mode to enable you to use the features you require.

Never be afraid to back yourself when trying new things, just always make sure you have 3 escape routes if things go wrong.
Level 1: Cadet

Re: Telstra C6300 port forwarding not working

I have the same problem.  Trying to setup a Unity Intercom system and cannot open the 20101 port on hte modem...




Level 2: Rookie

Re: Telstra C6300 port forwarding not working

Dear All,


After extensive troubleshooting I've a solution that fixes the port forwarding issue.


This might not fix everyone's port forwarding issue but it did mine....


Anyways.... Down to business...


If your port forwarding to a device thats been assigned an IP via DHCP (automatic IP) Port forwarding works

If your port forwarding to a device thats been assigned an IP manually (statically assigned) port forwarding fails


After a bit more testing I discovered


Using DHCP, the DNS server addresses being applied were Telsta's DNS servers...


Generally ADSL modems and routers set the DNS server addresses to that of the gateway address. In the case of our cable modem routers the DHCP server doesn't apply the gateway address to the DNS server address...


That said, it suggest that the cable modem router doesn't have a DNS server or DNS relay component in it.


Manually applying Telstra's DNS servers in the TCP/IP properties to those devices that have manual IP's, port forwarding began to work.


I use googles DNS servers as they are really easy to remember to all my manually assigned devices...


So if you have manual IP addresses assigned, manually assign a DNS server address (DON'T PUT IN YOUR GATEWAY ADDRESS) Port forwarding should start working afterwards...




Telstra Smart Modem

Plug in and connect in minutes. Smart.

Find out more